BD+C’s annual Giants 300 listings rank the U.S. and Canadian firms that designed or constructed the largest volume of commercial, institutional, industrial, and multifamily residential buildings in 2010. This spring, the editors surveyed the largest AEC firms, ranking the top 300 across six categories: architects, architect/engineers, engineers, engineer/architects, contractors, and construction managers. All firms are ranked by reported revenue for 2010. Please note: Civil engineering work (including roads and bridges), single-family homes, and certain building types (e.g., power plants, oil drilling rigs) are excluded from the BD+C Giants 300 financial data.—The Editors